Pearl Bailey’s voice was honey poured on charcoal—a sweet, deep rumble that somehow managed to sound at once nasal and resonantly chesty as the singer lightly tossed off Cole Porter and Johnny Mercer lyrics in the 1950s. But it was her deliciously wayward way of interrupting herself that endeared Bailey to audiences, and that’s what Roz White sensibly seizes upon as a storyteling device in her affectionate cabaret, Pearl Bailey…By Request. At MetroStage, where the show is receiving its world premiere, White quickly proves that when a song is pitched low enough, she can persuasively mimic the singer’s cadences and delivery. But what she’s really mastered is the way Bailey had of arriving at the last note of a musical phrase—the one most singers would hold for a beat or two—and tossing in chatty little asides about how her feet hurt, or how she planned to spend her paycheck, or how nicely the band leader was tickling the ivories tonight. For ’40s and ’50s audiences used to a more formal sort of big-band singing, this quirky, blues-inflected running commentary in Bailey’s act seemed amusingly confidential and personal. And of course, it meshes nicely with a tribute evening’s need to shoehorn biographical information into what would otherwise be a concert impersonation. The real Pearl didn’t interrupt herself nearly as much as her avatar does—the star’s manner was more languid, less frantic than White’s—but the asides still have the effect they once did, rendering the singer warm and human. With White calling on her jazzy four-piece band to solo not by name but by such less personal monikers as “piano-man” and “guitar-man,” the show’s clearly still a work-in-progress. But she’ll doubtless settle into the role, and she’s otherwise got “Personality” (as one of Baileys’s signature songs has it) to spare. Though Bailey had a storied career—singing and dancing in black nighclubs in the 1930s, appearing on Broadway and in films in the ’40s and ’50s, marrying white jazz drummer Louie Bellson—she’s probably best remembered by D.C. audiences for her 1968 renaissance in Hello Dolly, where she was brought in to head an all-black cast (with Cab Calloway) and revitalize a then-tired show. The company played at the National Theater prior to Broadway, and at the height of the Civil Rights era, it made national headlines when Lyndon Johnson dropped by for a matinee performance and Bailey crooned a chorus of his campaign song (“Hello Lyndon”) to him at the curtain call. Pearl Bailey…By Request doesn’t reference that moment (it does have on hand a sidekick, William Hubbard, who could probably do a creditable Calloway if asked), but it does capture the folksy, casual style of a star who thought nothing of breaking character to chat with audience members—presidents included—as if they were the best of friends.